Digital Geology and Lithology maps of the Strangways Range Region in the eastern Arunta Region of the Northern Territory have been produced from a scanned image of the first edition map published by the Bureau of Mineral Resources in 1984. The image was digitised using Microstation and ArcInfo software, and attributed to meet standards for Version 2004.01 of the Geoscience Australia Digital Data Dictionary for GIS Produces as closely as possible. The finished product has been provided as ArcView shape files and ArcInfo export files on CD-ROM. Extensive internal quality assurance and quality control processes have been used to verify the data.

A significant problem for ground-based gamma-ray spectrometric surveys is the effect of emanation radon on estimated uranium concentration estimates. Radon gas (a daughter product in the U238 decay series) escapes from rocks and soils near the earth?s surface into the lower atmosphere. Under early morning, still-air conditions, radon concentrates as a thin layer near the earth?s surface. If ground radiometric surveying is undertaken before this radon layer is mixed into the lower atmosphere, large errors in U concentration estimates result. This paper shows the effect of early-morning radon accumulation on a quad-bike gamma-ray spectrometric survey near Boorowa, NSW. Paddocks surveyed early-morning show much higher apparent uranium concentrations than those surveyed later in the day. We demonstrate the radon diurnal effect by recording the apparent U concentration at a fixed site over several weeks. Typically, there is a build-up of radon near the earth?s surface overnight. Radon concentration reaches a maximum at about 7 am before slowly dispersing over a period of 2-3 hours. The diurnal data also show the effect of rainfall on apparent U concentrations. Rain precipitates radioactive daughter products of atmospheric radon onto the ground resulting in a significant increase in apparent U concentration. These short-lived daughter products decay to insignificant concentrations within about 3 hours. Ground surveys should not be conducted within 3 hours of rain, or under early-morning, still-air conditions.

This report describes the geology of the area covered by the SKIPTON 1:100 000 sheet area (7522) in western Victoria. Geomorphology, stratigraphy, structure, metamorphism and economic geology of the area are described. Brief outlines of the regional geological setting and geological history are also presented. The Skipton 1:100 000 sheet area comprises an inlier of early Palaeozoic meta-sediments and intrusives, unconformably overlain by surficial Cainozoic sediments and volcanics. The exposed bedrock forms the westernmost part of the Lachlan Fold Belt. Exposed bedrock comprises Cambrian-Ordovician turbidites of the Warrak and Pyrenees Formations of the Saint Arnaud Group. These units were deformed and regionally metamorphosed to low-grade during the Silurian Benambran deformation and later intruded by Devonian fractionated I-type granite plutons. A transgressive fluviatile to marine sequence of Tertiary rocks overlies older units in the centre and west: units distinguished are the White Hills Gravel, Dilwyn Formation, Heytesbury Group and Moorabool Viaduct Sand. Quaternary units cover most of the sheet area and comprise basalt flows and scoria deposits of the Newer Volcanics, and a range of fluvial and lacustrine sediments including: older alluvial terrace deposits; older alluvial and colluvial deposits; colluvial deposits; swamp and lagoonal deposits; stream alluvial deposits; and lunette deposits. Late Pleistocene aeolian clay, the Windgelli Clay, forms a thin veneer over the most of the Palaeozoic rocks and the Newer Volcanics. The previously worked tungsten, gold, bismuth and silver - bearing vein deposit at Pittong is the only metalliferous occurrence known in SKIPTON. However, the area contains more significant nonmetalliferous deposits including the Pittong clay deposit and deposits of sand, granite, basalt, and scoria.

An area of approximately 32 square miles in the vicinity of Rye Park has been mapped in greater detail than that of previous regional surveys. Three possible tungsten-bearing areas have been delineated as warranting magnetometric and plane-table surveys. An extension of each of these three areas is indicated. Attention is drawn to copper, tin, silver, lead, and zinc mineralisation of the area, and it is considered that there are possibilities of finding payable orebodies containing these metals.

No abstract available

The following notes are intended to accompany Map No.1049, which has the same title as that given above. This map was prepared at the request of the Survey Directorate, L.H.Q., Melbourne, Department of the Army, and is primarily for the use of the Director of Survey, Advanced L.H.Q., Brisbane. The map is termed "provisional" since it is based on only a portion of the data available and the reductions have been made by approximate methods. Nevertheless since use has been made of that portion of the data which has been most recently observed it is considered the most reliable for most practical purposes. For some time work has been proceeding on a final map showing the distribution of magnetic inclination over Australia and the surrounding areas, and this map will be available in the near future.

No abstract available

The authors were engaged in geological reconnaissance work in the Fitzroy Crossing - Halls Creek area, during the period 16th August to 23rd September, 1948. The principal object of the investigation was to examine the area covered by the Mt. Ramsay Sheet of the Army Series. Work was extended beyond the limits of this sheet however in order to obtain information with regard to the age relationship of some formations, and a visit was made to the Wolf Creek Meteorite Crater 63 miles south of Halls Creek. During the survey, work was concentrated chiefly in mapping the distribution of rocks and different geological periods, determining their relationships and economic possibilities, and recognising areas warranting more detailed investigations. Accompanying geological plans and aerial photographs are included.

This second edition preliminary three dimensional model has been constructed from themes compiled from a variety of sources and assembled primarily within a GoCAD application. The display medium for web delivery has used the Virtual Reality Modelling Language (VRML) format. Layers of data were principally supplied by Geoscience Australia. Mineral occurrence information was provided by the Northern Territory and Western Australia Geological Surveys. Interpreted 1:250 000 scale maps of the Tanami and 1:500 000 Arunta North were provided by the Northern Territory Geological Survey. Cross-sections were geophysically modelled using ModelVision software and imported into GoCAD. Structural and geological modelling of cross-sections was provided by the NTGS. Surfaces were modelled in GoCAD using cross-section data and surface constraints. The current seismic proposal has been a collaborative effort involving Commonwealth, State and private companies.

GEODATA COAST 100K 1992 is a vector representation of the topographic features depicting Australia`s coastline, and State and Territory borders. The data have been derived from the 1:100 000 scale National Topographic Map Series and contain the coastline as depicted by the Mean High Water, seaward islands shown on the source material and State land borders. The coastline includes the main outline of the land and includes bays, the outer edge of mangroves and closes-off narrow inlets and watercourses at or near their mouths.